Lobesia botrana Scientific Name Lobesia botrana Denis & Schiffermüller, 1776 Synonyms: Phalaena vitisana Jacquin, 1788 Olindia rosmarinana Millière, 1866 Common Name(s) European grapevine moth, grape fruit moth, grape leaf-roller, grape vine moth, grape moth, vine Figure 1. Adult male of Lobesia botrana (Todd Gilligan, Colorado State University). moth Type of Pest Moth A Taxonomic Position Class: Insecta, Order: Lepidoptera, Family: Tortricidae Reason for Inclusion in Manual CAPS Target: AHP Prioritized Pest List - 2003 through 2009; PPQ Program Pest Pest Description European grapevine moth (EGVM) is primarily a pest on the flowers and B fruit of grape vines, but the moth has been known to infest stone fruit trees, privet, and olives as well. Survey for this pest in stone fruit, privet, and olives is important because, in general, these secondary hosts flower before grapes; and L. botrana can be found on these earlier hosts before moving over to grapes, its preferred host. Eggs: The egg of L. botrana is of the Figure 2. Larva (A) and pupa (B) of L. botrana (Instituto so-called ‘flat type’ with the long axis Agrario S. Michele All’ Adigen, HYPPZ Zoology). Last update: November 2014 1 horizontal and the micropyle at one end. Eggs are elliptical, flattened, and slightly convex. The egg measures about 0.65 to 0.90 mm x 0.45 to 0.75 mm. Freshly laid eggs are pale yellow, later becoming light gray and translucent with iridescent glints (opalescent). The chorion is macroscopically smooth but presents a slight polygonal reticulation in the border and around the micropyle (CABI, 2009; Gilligan et al., 2011). Larvae: From Gilligan and Epstein (2012): Figure 3. Male genitalia of L. botrana (Todd “First instar larvae are yellowish green Gilligan, Colorado State University). and approximately 1.0 mm in length. The head is black to dark brown, and the paler prothoracic shield is concolorous with the rest of the body. Last instar larvae are 10-15 mm long and vary in color from light yellowish green to pale brown. The head is brown to light yellowish brown to honey colored, the antennae and thoracic legs are brown to black, and the prothoracic shield is variably shaded with dark brown to black on the posterior and lateral margins. All instars have a dark stemmatal area and genal dash. Other diagnostic larval characters include: L-pinaculum on T1 horizontal, not extending beneath spiracle; SV groups on A1, 2, 7, 8, 9 with 3:3:3:2:2 setae; SD2 on A1-8 absent; distance between V setae on A9 approximately 1.5-2.03 the distance between V setae on A8; distance between D1 setae on anal shield equal to the distance between D1 and SD1; anal comb with 5-8 teeth; mandibles without inner teeth or a retinaculum.” 3 Pupae: Female pupae are larger (5 to 9 mm; approx. /16 to 3 3 5 /8 in) than males (4 to 7 mm; approx. /16 to /16 in). Freshly formed pupae are usually cream or light brown but also light green or blue, but a few hours later become brown or deep brown (Fig. 1B). Cast pupal skins, are somewhat unusual in retaining a greenish tint on the anterior abdominal segments. Figure 4. Female genitalia Pupal age may be estimated as a function of tegument of L. botrana (Todd Gilligan, Colorado State transparency and coloring (CABI, 2009). University). Adults: From Gilligan and Epstein (2012): Last update: November 2014 2 “Adults are not sexually dimorphic, although females are generally larger than males. Forewing ground color is cream; the basal one-half of the wing, which is well differentiated by the inner edge of the median fascia, is overlaid with leaden gray, gray- brown, and pale-brown scales forming irregular patches and incomplete fasciae. The dark-brown median fascia is well defined basally, but irregular distally; the distal one- fourth of the wing is paler. The hindwing is whitish with a brown periphery in the male; it is almost complete brown in the female. Males lack a forewing costal fold. Male genitalia are characterized by the following characters: socii short, lateral, with small tufts of setae; uncus, gnathos, and transtilla absent; valvae long and narrow with row of spines on the ventral magin; cucullus densely setose, separated from sacculus with a distinct gap in the marginal spines; sacculus weakly concave postmedially; aedeagus small; cornuti absent. Female genitalia are characterized by a long, slender ductus bursae that is undifferentiated from the corpus bursae and an elongate signum”. For an in depth description of pest stages, see Gilligan et al. (2011). Biology and Ecology The first flight of adults A B occurs in spring when daily average air temperature is above the minimal threshold temperature of 10°C (50°F) for 10 to 13 days. The second flight period begins in summer (USDA, 1985). In Israel, adults appear in the vineyard when grapevines Figure 5. Adult on grape fruit (A) and larvae feeding inside a grape flower. Adults are hard to (B) (Michael Breuer. http://www.bio- pro.de/de/region/freiburg/magazin/01476/index.html). discover during the day and may be noticed only when they take flight after being disturbed. They fly at dusk whenever the temperature is above 12°C (54°F), but rainfall and wind will reduce flight. Adults usually prefer hot, dry places protected from wind so they fly mainly between the first rows of grapevines close to windbreaks and on slopes facing the sun (Avidov and Harper, 1969). Within a day or two of mating, females begin to oviposit on the blossoms, leaves, and tender twigs of the grapevine. The female lays 300 or more eggs singly or in groups of two or three at a rate of more than 35 per day. During rearing experiments under laboratory conditions in Czechoslovakia, the optimum temperatures for oviposition were from 20 to 27°C (68 to 81°F) (Gabel, 1981). First generation eggs are laid on the flower buds or pedicels of the vine while second generation eggs are laid on individual grapes (USDA, 1985) (Fig. 5A). Eggs hatch in 5 to 10 days or 75 degree-days above a 10°C (50°F) threshold (Gilligan et al., 2011). Last update: November 2014 3 The European grapevine moth is a polyvoltine species (CABI, 2009). The number of generations in a given area is fixed by photoperiod together with temperature, acting on diapause induction and development rate, respectively. Short-day photophases (between 8 and 12 h) during the larval stage induce diapause in larvae that will be later expressed in pupae. The moth achieves two generations in northern cold areas and usually three generations in southern temperate areas, although this general latitudinal pattern is often modified by the altitude-derived gradient and/or microclimatic conditions in a given area. Thus the number of generations has a broader range, reported as one generation in Romania (Filip, 1986) to four generations (often partial) in Spain, Greece, Crete, Italy, and former Yugoslavia (Coscollá, 1997 and references therein). Five generations have been reported in Turkmenistan (Rodionov, 1945). First generation larvae feed on bud clusters or flowers and spin webbing around them (glomerules) (Fig. 6) before pupating inside the web or under the rolled leaf. Second generation larvae enter an unripened grape (Fig. 4B) and feed before pupating inside the grape. Larvae of the third generation, the most damaging, feed on ripening grapes, migrating from one to another and spinning webs. The third generation larvae leave the fruit and shelter under the bark, among dead leaves, or between clods of earth, where they pupate before overwintering. Few of these larvae pupate before harvest, and many are gathered with the grapes. Larval development is completed in approximately 20 to 28 days or 170 degree days for larvae feeding on flowers and 225 degree-days for larvae feeding on berries (Gilligan et al., 2011). Pupae complete development in approximately 12 to 14 days, or 130 degree-days, for non-diapausing individuals (Gilligan et al., 2011). Moth activity (i.e., flight, feeding, calling, mating, and egg-laying) is principally displayed at dusk, although some activity can also occur at daybreak or at any time on cloudy days. Water availability is necessary for adults to reach their potential reproductive output (Torres-Vila et al., 1996). Damage Grape: On grape inflorescences, neonate (first generation) larvae firstly penetrate single flower buds. Symptoms are not evident initially because larvae remain protected by the top bud. Later, when larval size increases, each larva agglomerates several flower buds with silk threads forming glomerules visible to the naked eye (Fig. 6), and the larvae continue feeding while protected inside. Larvae usually make one to three glomerules during their development. Despite hygienic Figure 6. Glomerules of L. botrana (EFAPO-ES). Last update: November 2014 4 behavior of larvae, frass may remain adhering to the glomerules. On grapes (summer generations), larvae feed externally and when berries are a little desiccated, they penetrate them, bore into the pulp, and remain protected by the berry peel (Fig. 5B). Larvae secure the pierced berries to surrounding ones by silk threads in order to avoid falling. Each larva directly damages several berries (one to six). If conditions are suitable for fungal or acid rot development, a large number of berries Figure 7. Damage by L. botrana (HYPPZ near the damaged berry may be also Zoology). affected. Damage is variety- dependent; generally it is more severe on grapevine varieties with dense grapes because this increases both larval infestation and rot development. On both inflorescences and grapes, several larvae may co-exist in a single reproductive organ. Larval damage on growing points, shoots, or leaves is unusual.